645815451 has 8 divisors (see below), whose sum is σ = 872883280. Its totient is φ = 424645632.

The previous prime is 645815437. The next prime is 645815461. The reversal of 645815451 is 154518546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645815451 - 2⁵ = 645815419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645815461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1474246 + ... + 1474683.

It is an arithmetic number, because the mean of its divisors is an integer number (109110410).

Almost surely, 2^645815451 is an apocalyptic number.

645815451 is a deficient number, since it is larger than the sum of its proper divisors (227067829).

645815451 is a wasteful number, since it uses less digits than its factorization.

645815451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2949005.

The product of its digits is 96000, while the sum is 39.

The square root of 645815451 is about 25412.8993033066. The cubic root of 645815451 is about 864.3762199535.

The spelling of 645815451 in words is "six hundred forty-five million, eight hundred fifteen thousand, four hundred fifty-one".